Automatic door-lock for fire-doors.



H. SCHERER. AUTOMATIC DOOR LOOK FOR FIRE DOORS.

APPLICATION FILED JAN. 30, 1914.

Patented Ja11.26, 1915.

HE Nwmm PETERS C0. PHOTO LITHQ, HIAbH KINITED STATES PATENT I-IEhTRYSCI-IERER, OF BILLINGS, MONTANA.

AUTOMATIC DOOR-LOCK FOR FIRE-DOORS.

Application filed January 30, 1914.

To all whom it may concern:

Be it known that I, HENRY SOHERER, a citizen of the United States,residing at Billings, in the county of Yellowstone and State of Montana,have invented new and useful Improvements in Automatic Door- Locks forFire-Doors, of which the following is a specification.

This invention relates to improvements in door latches and especially tolatches for use on furnace doors and stoves.

One feature of my invention consists in the novel means employed to holda door or gate in a specified position, either opened or closed.

Another feature is the use of novel means to hold the fire door of astove or furnace in its closed position, but not absolutely lockedagainst force applied from within the furnace.

Another feature of the invention consists in the shape of the receivingcam and the positive means employed for holding the .cam in itsreceiving position.

Heretofore trouble has been experienced in the operation of furnaces notonly from the weight of the doors to be lifted in opening or closing thefurnace but because no adequate device has been provided for allowingthe door to be opened or closed with but slight effort on the part ofthe operator. where explosions have occurred within furnaces and thedoor has been locked shut, as is the case where the ordinary furnacedoor is lifted up and over an incline and its latch drops into a recessagainst the door frame. To open such a door a vertical motion isnecessary before the door may be swung open horizontally. Hence one ofthe objects of my invention is to provide a door latch which may beoperated equally well from either side of the door and thereby avoid thedanger of confined explosions and the resulting damage.

The invention consists in the novel construction of parts illustrated inthe accompanying drawings and described and claimed in the followingspecification and claims.

In the drawings-Figure 1 is a face view of a furnace door illustratingthe latch parts in engagement. Fig. 2 is a side view of the same doorshowing the door resting against the front of the furnace in its latchedposition, and illustrating in dotted Specification of Letters Patent.

This has been especially true- Patented Jan. 26, 1915.

Serial No. 815,445.

lines the position of the latch parts when the door is opened. Fig. 3 isa face View, enlarged, of the receiving block. Fig. 4 is a side view ofthe same block shown in Fig. 8.

1 represents the front of a furnace with a door frame 2 and door 3mounted on suitable hinges 4-. Attached to the door but spaced therefromto prevent heating is a handle 5. Fastened to the front of the furnaceand adjacent the door frame 2 is a bracket 6, and pivotally attached tothis bracket 6 by means of a bolt 7 is a cam receiving block 8. It willbe observed that the lower part of the block 8 is divided into the forks9 and fitted astride of the bracket 6. The upper portion of the camblock 8 is re cessed at 10 and the lower portion between the forks isshouldered at 11. Rigidly mounted on the door 3 and extendinghorizontally therefrom so as to swing over the bracket 6 is a keeper bar12 arranged to enter the recess 10 of the cam block 8.

Block 8 is always in a position to engage with and receive the bar 12and needs no attention from the operator. When the door is opened theshoulder 11 of the cam block 8 rests on the forward portion of thebracket 6, (Fig. 2) and the recess 10 is in the same horizontal plane asthe bar 12. In the operation of the device, the door is given a closingmovement, the bar 12 engages the recess 10 and block 8 and rides up andover the pivot point of the block, lifting the door with it and finallybringing the door to rest against the furnace front. At this point theweight of the door keeps it shut. As the bar 12 is carried by the block8 there is a frictional movement between the two parts, the block 8having a rotary movement relative to the bar 12. Any explosion fromwithin need exert only sufficient force to push the weight of the doorpast the pivot point of the block 8 to open the same. When the door ispulled open past the pivot point the bar 12 leaves the recess 10 and theblock 8 rests on the bracket 6 as previously described.

From the foregoing it will be seen that my invention provides a latchwhich needs no attention to keep it in order, and further that it isalways in operable position and but little efiort is necessary, themomentum of the door on closing being sufficient to carry it over thepivot point of the cam re ceiving block. In my door latch a simplehorizontal pull on the door is suiiicient to open it. It will be noticedthat the weight of the door on the cam block is suflicient to hold thedoor in a latched position under ordinary circumstances as against theopen ing action of falling coal within a furnace or if used in gateconstruction of wind against a gate; further that it readily yields to aforce sufficient to overcome its weight against the cam and door frame.The horizontal force required to open the door may be gaged by thedistance between the furnace front and the pivot point of the block 8 onthe bracket 6, it being obvious in the manu-, facture of the door latchthat as this point is moved from the door frame the block will morenearly assume a horizontal position and the resultant propping actionagainst the doorwill be more evident. It will be further observed thatall parts used in the invention are strong and heavily con strueted,thus eliminating any danger of breakage or war-ping due to heat or othermisuse.

Particular attention is called to the fact that while I have illustratedthe latch as ap-. plied to a furnace door the construction is equallywell applicable for use in any type of door, gate or window, whetherswinging orsliding. Any desired changes may be made in the size andproportion of the part without departing from the scope of my invention.

Having described my invention, what I,

her to swing in the general direction of the movement of the door andengage said extension to, lift the. door up and over the pivot and downinto closed position, the door bearing inwardly and downwardly againstthe door frame.

2. The combination with a door and a door frame constituting twomembers, of an extension on one member, and a receiving block providedwith a notch pivotally mounted on the other member to swing in thegeneral direction of the movement of the door and engage said extensionwith said notch to lift the door up and over the pivot point and downinto the closed position, said. receiving block rotating with respect tosaid extension, there being a frictional engagement between the surfaceof the notch in the receiving block and the projection during thismovement.

8. The combination. with a door and. a door frame constituting twomembers of an extension on one member and a receiving block providedwith a notch pivotally mounted 011 the other member to swing in thegeneral direction of the movement ofthe door, and engage said extensionwith said notch to lift the door up and over the pivot point and downinto the closed position, said receiving block being provided with ashoulder to engage the member upon which it is mounted to prevent themovement of the notch beyond the horizontalplane of said extension whenthe door is-opened,

In testimony whereof I aiiix my signature in presence of two witnesses.

HENRY SCHERER. Witnesses O. H. BnoWN, E. S. COLEMAN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

